On Thursday, about an hour after the bill was posted online, NBC's Chuck Todd tweeted that a group of a conservative Republican senators were meeting, and that there are at least three GOP senators, and possibly more, who plan to announce later today that they will oppose the bill.

If that number proves to be accurate, it could be a death blow to the bill.\

Sen. Rand Paul, R-Tenn., told NBC that he and several other members of the GOP caucus would be making a statement on the bill later Thursday.

"It looks like we're keeping Obamacare, not repealing," said Paul, who declined to say whether that meant he would vote against the bill.